If you are handy with wires and such, you can make a crossover cable out of a regular ethernet cable. That's what I did in college when ethernet cables were handed out freely. To do this, cross solid orange with solid green and striped orange with striped green inside the cable, or do it at one of the terminations.
Note: this cable will likely be out of spec and not as fast as a real crossover cable. Hell, when I made mine, I just twisted the wires together and taped the hell out of the thing. It worked.